


Born to Run, Break the Mold

by agentofreedom



Category: Harry Potter - J. K. Rowling
Genre: Alternate Universe - Canon Divergence, Family Feels, Gen, Horcruxes, Hurt/Comfort, Regulus Black Lives, What-If
Language: English
Status: In-Progress
Published: 2019-12-06
Updated: 2020-06-07
Packaged: 2021-02-25 22:00:28
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 4
Words: 11,642
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21692659
Author URL: https://archiveofourown.org/users/agentofreedom/pseuds/agentofreedom
Summary: Regulus closed his eyes briefly with a very slight grimace. "I'll admit… it wasn't my most thought-out plan." His voice was hollow; his eyes, shadowed. "Or a plan at all."Sirius had to let out a disbelieving laugh. "I thought I was the reckless one. Never thought I'd see the day where Regulus Arcturus Black dives headfirst without thinking… and to the estranged Black sheep of the family, too. You really are setting records for the history books today."He wasn't sure why that was hilarious (well, he did think he was quite funny, of course, but not byRegulus'sdry standards), but the younger Black started chuckling - darkly - and then didn't stop.
Relationships: James Potter/Lily Evans Potter, Regulus Black & Sirius Black, Sirius Black & James Potter, Sirius Black & Remus Lupin
Comments: 97
Kudos: 431





	1. One

The sun had long set over the small sleepy town along the coast of Somerset, draining away the summer heat of the day as most of the residents gladly opened their windows to let in the slow cooling breeze. One house, however, did not open its doors nor any windows; it perched neatly on a rise facing the sea and was quite isolated from its neighbours, just as its inhabitants themselves were. They had occupied the quaint red-bricked house a week ago but that was all anyone in the town knew about them. They surely were not aware that the young couple were a witch and a wizard, only recently out of school and even more recently wed. 

Yes, James and Lily Potter had picked out quite a lovely first home. 

Sirius was aware of this, of course, but he had not yet commented on the house itself, for he was too busy lamenting over his preening best mate. 

"I'm telling you, Prongs, this is how it starts. This is the beginning of the end, the slow yet sure descent into-"

"For God's sake, Sirius, all he's done is assemble the kitchen cabinet." 

James's self-satisfied grin at his job well done slipped into a look of betrayal as he swiveled around to stare at his wife, leaning against the kitchen door frame with a smirk of her own. 

" _All_ I've done? Lily! 'Twas no small feat!" 

"Yes, well," his wife replied wryly, "you did insist on doing it the Muggle way, and you've never so much as screwed anything in your life, so… Oh, do shut up, Sirius."

She levelled Sirius with a flat glare but he only waggled his eyebrows and smirked wider at James. "Ah, Prongs, a month into marriage and you _still_ haven't-?" He tutted, a thoroughly disappointed sound that only dissolved into a bark of laughter as James whacked him upside the head with the manual for the kitchen cabinet. 

"Padfoot, mate," he said, pushing his glasses firmly up and eyeing his best friend with a thoughtful, pointed look. "I reckon you're looking a bit peaky on this fine night, _I_ think you're overdue on that beauty sleep I know you so rely on." 

Sirius patted him on the cheek twice, then winked at an amused Lily and said in conspiratorial tones, "Despite common belief, it _does_ take effort to always look this good." And then he lifted his hands in mock-thanks and backed up towards the fireplace, reaching for the floo bucket - because it really was getting late after the wild day they'd all had on Order duty, and _not_ because he needed his beauty sleep.

"Cocky twat." James shook his head, and Lily chuckled, raising her her hand in farewell. 

"Tell Remus to drop by after his mission," she reminded Sirius. "I miss sensible conversations."

Sirius threw James a bewildered look. "Blimey, mate, you're _really_ falling short here - no sensible conversations _and_ no screwing? Ah, we tried to warn ya, Evans."

And with that, he called out his address and jumped into the Floo before James could do more than call out "It's _Potter_ now!", leaving them with another bark-like laugh echoing in their kitchen.

*

Sirius was still laughing when he stepped out of his fireplace into the living room of his own flat - a dingy fifth-storey thing on the outskirts of London - only for the sound to die abruptly in his throat, like someone had hit his off-switch, and his wand to appear in his hand, pointed at the intruder standing before him and ready to fire off a Stunner. 

"Sirius."

The voice, weak though it was, halted the spell on Sirius's tongue. His mind backflipped to catch up and he could do no more than stare, dumbfounded, as the hooded figure swaying - and dripping? - in the middle of his home slowly raised his bare hands. Sirius's eyes flicked between them and the person's face, not quite letting his guard down despite the dreadfully familiar voice, and jerked his wand in the direction of the hood. 

"Show me your face." His voice was flat, no sign of the lighthearted laughter that had filled it mere moments ago. 

The figure - the boy - seemed to hesitate, but when Sirius's hand tightened imperceptibly around his wand and raised it a few inches, he heaved a resigned sigh and lifted a hand to slowly pull down his hood. 

Sirius had to fight every urge in his body not to drop his wand then and there and dive across the room. Instead, he stood up straighter, jaw clenched, and took in the battered, weary, but no less defiant, face of his younger brother. "Regulus." He steeled himself, then said sharply, "When was the last time we saw each other, alone?"

Regulus clenched his fists tightly. "A week before I graduated, Dumbledore called us to his office." His own searching gaze pierced into Sirius, whose brain was starting to catch up to the absurdity of his current situation. "For the news that our father had passed away."

It was him. No one else, even if they had that particular tidbit of information, would have conveyed the exact amount of grief and anger that flashed through his grey eyes at the memory. Sirius's relief at confirming his brother's identity was extremely brief. He lowered his wand a bit and marched forward to get a closer look at his face, equally unnerved by the unflinching - almost daring - stare (when had Reggie grown a pair?) and the fact that he'd _found Sirius's flat_. 

"Well, shit, sit down before you pass out on me," Sirius muttered, kicking out one of the rickety dining chairs, and waiting pointedly until Regulus gave in and collapsed into the seat. Sirius crossed his arms and stared down at him, noting with growing bewilderment the pool of water forming on the tiled floor mixed unmistakably with blood. "Okay, firstly, what the _bleeding hell_ happened to you, and how in Merlin's name did you get in here?" 

Regulus let out a dry laugh, clasping his hands in his lap - the only visible sign that he was as tense as his brother was feeling. "Your security's nothing on Father's charms."

Sirius felt a twinge of annoyance that he hadn't sensed in a long time, family-related as it was. "They've kept _your_ lot away after three of my mates' homes were attacked, so I'd say they're a bit more than nothing," he couldn't help but retort. Regulus's face twitched, as if he found that funny, and Sirius wanted to hex the smirk off his face.

"Yes… my lot." 

Sirius stared at him. What was that supposed to mean? What was he deflecting? And-

It occurred to him that he hadn't even made certain that Regulus was alone, that this wasn't an ambush, but the thought had no more passed his mind before he brushed it off. No, this was no ambush. He eyed the bruises blossoming over his brother's face, up his neck, the cuts and scrapes on his hands, the tight way he held himself that Sirius only noticed because he knew where to look. 

No. This was an escape. 

But from who- or what?

Knowing he would not get a straight answer if Regulus had already deflected his first question, he jerked his head at Regulus's hands. "Show me the worst of it. You know I'm decent at healing charms." 

But he might as well have claimed that he was going to take Regulus in - his brother froze, clenched his hands tighter, and glared up at Sirius. "I'm fine," he said coldly. Or tried to, but he was shivering, and looking weaker by the minute. Sirius couldn't see a deep wound anywhere, but magic - especially dark magic, which he had a nasty feeling was involved here - did not always leave physical traces. 

"Sure, you're just transforming my living room into a pool of blood for shits and giggles." He summoned his healing kit and pulled another seat out to sit down in front of his brother. He scowled at Regulus in warning before grabbing his arms and pulling them away from his body, looking for open wounds first. 

" _Sirius_ , I said-" Regulus growled, pulling his wrists back to no avail. 

"Shut the hell up, Reg. You wouldn't be in _my_ house if you were fine, looking the way you do now!" Sirius shot back, tapping his wand at the jagged cuts on his hands and muttering the spells to clean and heal them. "If you won't tell me how this happened then- oi, what the _f_ -"

"I _told_ you-!" Regulus managed to tug his hands back and folded them protectively over his chest. " _I'm fine_." His chest was starting to rise and fall rapidly. His eyes unfocused as they stared at the floor below his shoes, the puddle of bloodied water. Sirius stared at the top of his head. 

"You're not," he said lowly, feeling sick in the stomach. Those… on his arms… Those weren't just bruises. They were - unmistakabley - handprints. "Reg. Who did this to you?" He didn't get an answer beyond shallow breaths. Sirius felt a familiar cold rage bubbling in his chest. "It was them, wasn't it." It wasn't a question. The turning in his stomach threatened to claw up through his chest and choke him. _His little brother, thrown into the snake's pit._

The shallow raggedy breathing from Regulus snapped his focus back, helped him push his fury and nausea temporarily down ( _I left him there_ ). Regulus's shivers were getting more intense, his hair falling limply over his downturned face, still dripping, and Sirius swore at his own slowness. He impatiently waved his wand in consecutive drying then warming charms before also vanishing the pool at their feet. Then he nudged at Regulus's leg to get his attention. Regulus jumped at the contact.

Sirius caught his eye and jerked his head towards the well-worn couch that had seen many a-recovering boy sleeping on it, usually after full moon nights. "Get over there and lie down, would you. I'm not having you keel over in my bloody flat." _Especially without any answers so I know whose arse needs a thrashing._

He had to bite down a quip when Regulus actually complied without argument, but the anxiety clawing at his chest was stronger; his brother was hiding it well but he was still racked with shivers despite being warmed up, and when he rose from the chair and headed to the couch, his steps were measured like he wasn't sure the floor beneath him was solid. He didn't even lift his eyes.

Sirius watched him carefully until he was perched gingerly in one corner of the long couch with his arms crossed over his chest again. He had a sudden feeling that he was looking at a petulant 8-year-old Regulus trying to hide that he was sulking about being told that he and Sirius would not start Hogwarts together. Their lovely parents never took well to sulky fits. Or anything much, really.

He blew out a heavy breath and dropped his face into his hands, scrubbing at his eyes roughly for a moment before piercing a glare at his brother. Regulus heaved his own sigh and looked back at him; the length of the living room between them felt like an impenetrable trench. But Sirius was nothing if not stubborn. 

"You're lucky no one else came through my floo while you were here," he eventually muttered darkly. 

Regulus closed his eyes briefly with a very slight grimace. "I'll admit… it wasn't my most thought-out plan." His voice was hollow; his eyes, shadowed. Sirius saw him swallow and flick a quick look around the flat but clearly not seeing any of it. "Or a plan at all."

Sirius had to let out a disbelieving laugh. "I thought _I_ was the reckless one. Never thought I'd see the day where Regulus Arcturus Black dives headfirst without thinking… and to the estranged Black sheep of the family, too. You really are setting records for the history books today."

He wasn't sure why that was hilarious (well, he did think he was quite funny, of course, but not by _Regulus's_ dry standards), but the younger Black started chuckling - darkly - and then didn't stop. Sirius sat up and eyed him. Regulus leaned back on the pillows and slipped a hand over his pocket, the laughter dying and leaving a slightly manic gleam in his eyes. "You may be right, brother."

Sirius knew what that look was. That was purely, ' _oh, if only you knew what I'd just done_ ', and he'd seen it enough times in the mirror to know that _nothing_ good could be behind it. Except, what on earth could _Regulus_ have done?

"I always am," he replied, cautious but not wanting to spook him again like before. The walls had not quite fallen behind Regulus's mask but Sirius had learned to find his cracks long ago. "But since you did come here…" _You need my help_. He rose to his feet suddenly, startling his brother out of his reverie.

"What are you…" Regulus watched him stride to the front door and the windows, pulling them open a crack to peer outside, then shutting them briskly and muttering his strongest shielding charms and security hexes, reinforcing what he'd had in place (plus a few extras) before Regulus had apparently slipped through them like they were nothing. 

"While I doubt any of your old pals will assume you're with _me_ , I wouldn't put it past, say, lovely Bella to come looking here anyway, and if you could track me down I've no doubt she can," Sirius replied darkly, twirling his wand as he deliberated over his fireplace before pointing his wand there too. "I'll block the floo for tonight. If Pro- the others need me, they know how to reach me." 

"You needn't worry." Regulus's voice was distant. Sirius turned to look at him sharply. "No-one's looking for me. Nobody will."

There was a chilling finality to it. 

Sirius stared as another shiver wracked through the younger Black's entire body, before striding forward to grab his shoulder, forcing him to make eye contact. Regulus recoiled but Sirius held him firm, jaw clenched. "What the _hell_ is that supposed to mean?" The rage he'd shoved aside before was coming back in waves, but colder and more chilling than ever. "Reg, what did you _do_?" He shook his brother's shoulder once more roughly but when he saw his face pale even more and his hands clench around the couch edge beneath him, he swore and let go, stepping back. Regulus's mask was cracking, his eyes flickering between Sirius's and the floor, and if he held himself any tauter he would _break_. Sirius tamped down the urge to shout at him. He let loose a shaky breath instead and shoved his hands into his hair, pacing up and down in front of the couch before he could take the silence no more and turned back to a wary Regulus, who was looking worse than ever, pale and clammy and stiff as a board. _Shit_ but where was he even supposed to _start_? 

"You…" Sirius scowled again, tugging at his hair once and waving his hand in frustration at his brother. "You gotta give me _something_ here, Reggie."

The old nickname made Regulus flinch back, loosening his shoulders as he fell back into the pillows once more. He closed his eyes and tilted his head back, looking _years_ older than 18. 

"Suffice to say…" he said in soft, measured tones. Sirius was not fooled. "That when I don't show up again where I'm expected… the assumption will be that I was… disposed of, shall we say…" Sirius's insides froze over. Regulus didn't open his eyes, though a mocking smile tilted a corner of his mouth, humourless though it was. "Perhaps word will spread that I fled."

Sirius’s throat felt incredibly dry. He licked his lips. "But you didn't." It was not a question. 

Regulus opened his eyes at last, and Sirius was not prepared for the depth of pain that was in them. "I guess it depends on your definition of the word." His words barely reached Sirius; there was something terrifyingly Dark playing behind his eyes and, vague though his answers were, it tore at something deep in Sirius's chest. 

It did not take a genius to read between the lines, whether Regulus meant to admit it or not. 

It was clear, painfully so, that whatever his little brother had gotten so entrenched in with Voldemort's side, that he had not planned to live through it. 

**Notes for the Chapter:**

> Ah, them delicious Black brothers feels...
> 
> Make sure you follow the story to get the next update (hopefully soon, as it's mostly written already!) and, of course, constructive criticism is always welcome, though I will state here that I really am primarily writing this for my own benefit and sharing it is just a bonus ;) 
> 
> I'm always down for discussions about my favourite emotionally repressed idiots though so feel free to rant at me!
> 
> And thank you for reading :)


	2. Two

**Summary for the Chapter:**

> And, try as he might, he could not shake the nausea turning his stomach at the certainty that - had Regulus indeed disappeared, had word spread from the Death Eaters to the Order that he had gotten cold feet and been killed for it - he, Sirius, would have accepted it without question. Oh, he would have grieved, certainly. He felt a glimmer of that grief now, remembering the once-bright-eyed kid that Reggie had been, following him around obediently, his (once-adored) big brother. He would have grieved hearing of his brother’s untimely demise, but he would have grimly chalked it down as yet another tragedy, another young loss in this Merlin-forsaken war, and he would have moved on. He had lost friends, he had lost classmates, and fellow Order members, most due to their resistance against Voldemort’s forces; and his brother had been on the wrong side for years. Sirius had to admit that in some part of his mind he had not expected his brother - his soft, idiot brother - to truly make it far with the Death Eaters.

It was bordering on 3am and Sirius had not slept a wink. He was certain that Regulus wouldn't have slept either, except he'd slipped some Dreamless Sleep into his pumpkin juice earlier and watched as his brother succumbed to the potion's pull, dozing off on the couch. He knew it was the only way to get his extremely tense brother to get the rest that he clearly needed; also, he needed a chance to peer at Regulus's wounds to ascertain there wasn't anything deadly. 

Thankfully, they were only more scrapes, cuts, and bruises. But most of the bruises were like the handprint ones on his wrists - up his arms, around his legs, and most horrifically around his collarbones and neck. Sirius had healed the cuts and spread a salve over the bruises before wrapping them all up and throwing a blanket over his brother, but as he sat in the armchair adjacent to him he could not shake the imprint of those handprints from his mind. 

What had been dragging Regulus, and where?

His words from earlier kept dredging themselves up in Sirius’s mind, taunting him with the alarming finality that Regulus had uttered them.

_ No-one’s looking for me… Nobody will… _

And, try as he might, he could not shake the nausea turning his stomach at the certainty that - had Regulus indeed disappeared, had word spread from the Death Eaters to the Order that he had gotten cold feet and been killed for it - he, Sirius, would have accepted it without question. Oh, he would have grieved, certainly. He felt a glimmer of that grief now, remembering the once-bright-eyed kid that Reggie had been, following him around obediently, his (once-adored) big brother. He would have grieved hearing of his brother’s untimely demise, but he would have grimly chalked it down as yet another tragedy, another young loss in this Merlin-forsaken war, and he would have moved on. He had lost friends, he had lost classmates, and fellow Order members, most due to their resistance against Voldemort’s forces; and his brother had been on the wrong side for years. Sirius had to admit that in some part of his mind, he had not expected his brother - his soft, idiot brother - to truly make it far with the Death Eaters. Hadn’t he uttered as much to James, one long solemn night ages ago, one of the only times he’d mentioned his brother since he left Grimmauld Place?

But now… 

What was he supposed to think, now? Looking at Regulus’s face, brows furrowed even in the midst of Dreamless Sleep, cheeks sunken in, hair in disarray, apparently having just escaped an uncomfortably close encounter with death… Sirius felt a sharp spark shoot up his arm and startled; he had clenched his hand too tight around his wand in his anger, and red sparks shot onto his left arm where it rested. He forced himself to release it, dropping it on the small table next to his chair, and rubbing his forearm grimly. 

“What have you gotten yourself into, Reggie?” he breathed out. A moment later, he paused, lifting his gaze from his left arm to his brother, pondering. 

The Order had a theory, with minimal evidence, of communication between the Death Eaters and their leader. Two months ago, Moody had killed one of Voldemort’s ‘inner’ men - or so their intel told them - in a bloody battle. They had fought off his mates who eventually escaped, and upon inspecting the dead Death Eater (underneath the ghastly mask they identified that it was one of the Rosiers), they had found an imprinted Dark Mark covering the inside of his left forearm. It had been red upon his death and had slowly darkened into black. Benjy Fenwick, their expert cursebreaker, had cast a few revealing spells on the incredibly Dark magic behind the Mark and had apparently confirmed Dumbledore’s theory that it was used as some sort of communication. The confusing part was that this was not the first Death Eater they had caught or killed, but the first to have this Mark. Dumbledore had seemed to deduce that it confirmed this particular member’s involvement as part of Voldemort’s ‘inner circle’ of followers.

But he hadn’t noticed - or paid attention - if Regulus also had one.

He felt even sicker at the thought, and he hadn’t thought  _ that _ was possible.

A few frozen moments passed before Sirius could muster up the energy to pull himself from the chair and take the few steps towards his sleeping brother. He pulled the blanket away and grabbed Regulus’s left arm from the wrist cautiously - he had pulled up the sleeve just enough to glimpse a blank forearm, when Regulus’s whole body went tense and he wrenched his arm from Sirius’s grip with a heart-stopping scream of pure  _ terror _ . 

Sirius jumped back, throwing up his hands instinctively - Regulus’s scream cut off in a gasp and a litany of ‘ _ no no no _ ’s that chilled the blood in Sirius’s veins but - most horrifically of all - he was still caught in the midst of sleep.

“Regulus-” he tried calling over his brother’s choked pleas, “Reg- Snap out of it!”

But he realised, with increasing panic, that the Sleep potion would not have worn out yet, and if it was meant to prevent Dreams ( _ nightmares _ ) then Regulus’s reactions were not because he was dreaming, but- he was remembering-

_ Regulus recoiling under his grip on his shoulder; Regulus’s face paling, his hands shaking; Regulus wrenching his arms out of Sirius’s hold as shivers wracked his body- _

_ Regulus’s arms, torso, neck, grabbed, clawed at, hard enough to leave bruises, imprints, trauma _ -

Presently, Reg’s face screwed up in obvious fear, eyelids fluttering, then screwing shut even more, arms wrapping around his body, curling up, defensive, terrified noises between his pleas, and Sirius could think of nothing besides getting his brother out of this state, and so he pointed his wand at Regulus and choked out, “ _ Ennervate! _ ”

Regulus jolted out of unconsciousness, half-falling off the couch, tangled in the blanket and throwing his arms out as if to defend himself from an assault. He cried out a loud, “ _ No _ !” and it seemed to jerk him out of his terrified daze. Sirius held himself frozen in his spot, not daring to reach out and grab his brother’s shoulder to steady him as was his instinct. 

There was a very long moment where Regulus slowly lifted his head and caught his brother’s (no doubt shocked) stare, and could do nothing but stare back, the only sound his panting breaths. Sirius clenched his fists; Regulus was no more than a couple of metres away, but his stare was far,  _ far _ , from this room. He saw, once again, that Dark  _ something _ deep in the murky grey so like his own.

Sirius could take the silence no longer. He licked his dry lips. 

“Not, uh… Not my best idea, that.”

Regulus blinked. He seemed to focus and actually see Sirius in front of him, and startled. “What…” His voice cracked on the word; he swallowed and sat up properly, gingerly loosening his crossed arms and shaking his head a bit. 

He paused, looking at where he was asleep a few moments ago, and then back at his sheepish (and tense) brother, an accusation in his eyes.

Sirius silently debated denying having drugged his younger brother to sleep, but that would probably (almost certainly) shoot his already rocky trust to shreds. 

So he folded his arms instead and shoved his guilt down.

“Well, you looked like utter shit, and you can’t tell me you would’ve slept without a potion.”

Merlin knows they’d had this treatment from Pomfrey enough to know they couldn’t really argue. Dreamless Sleep was the  _ least _ offensive potion one could be given. 

Regulus scowled at him, but Sirius couldn’t see past his shaking hands curled tightly on top of his knees. 

He sighed and let himself drop back down into his chair, wincing at the pull of his tight muscles - he’d been up for almost 48 hours by now. That never felt great. 

“Look,” he said wearily, deciding a change of tone would yield more results from his closed-off brother. “I don’t know exactly what sort of Dark shit you were caught up in. But you have to know I’ll help, whatever it is, alright?” He scrubbed a hand roughly down his face, banishing a brief thought of what to tell James if he decided to call. There was no time for that now. He looked back at Regulus, who was now eyeing him, but Sirius could not tell what he was thinking. He spread his hands out. “Say something, man. You’re creeping the hell out of me.”

Regulus huffed out a breath - it was not a laugh, but Sirius took it as a good sign. Any reaction was better than no reaction. “I…” His hand lingered over his pocket again - Sirius wondered if he should have been checking  _ that _ instead of looking for a non-existent Dark Mark. His eyes snapped back to his brother’s face as his voice strengthened, seeming to come to a decision. “You cannot tell  _ anyone _ I am here, Sirius. If word got back to the Dark Lord after he notes my absence, then… he’ll know…” His voice faltered here. Sirius bit down on his impatience and instead nodded slowly.

“Look,” he eventually said when it looked like Regulus was getting lost in that thousand mile stare again. “I’m not keen on painting a bigger target on my back than the one I’ve already got. Contrary to popular belief, I do have  _ some _ preservation instinct floating around here somewhere," he said wryly, waving a hand around his head. Regulus didn't smile. 

"What I need is- information," he said firmly, coming back to himself. 

Sirius quirked an eyebrow. "On?"

But Regulus shook his head. "It's not- I can get it myself. I have the books. Just… hidden away. I need to get them  _ here _ , and before my absence is noted." He hesitated. "I will wager perhaps two to three days until then."

"So… where are they hidden, and how do we get them?" 

Regulus looked into his brother's eyes and said, in a grave voice, "Grimmauld Place."

Sirius stared back and swore. 

**

It was an hour out from sunrise; the air was chilly, the street silent, the sky clear but for the odd bat flying past. Above him, Number Twelve Grimmauld Place loomed like a sceptre; cold and deadly, it reeked of Dark magic.

The last part may have just been Sirius's stark hatred for the place and everything it stood for. 

Nevertheless, he edged his bike around to a narrow alleyway beside Number Thirteen, parked it and took off his helmet, hanging it off the handlebar with care. He shook out his hair and clutched his wand grimly as he approached the old Black family home. The last time he'd stepped in here had been the summer before sixth year. He'd had no intention of ever returning. But…

Well. It was his idiot of a brother, and Sirius was shit at saying no - self-preservation be damned. 

Regulus's room had the west-facing window on the third floor. At this time or night - or morning - their mother would definitely be asleep and Kreacher would not dare venture upstairs lest he wake her. Regulus had recited the daily routine at Grimmauld Place with a specificity that would have unnerved Sirius if he wasn't just relieved at how very familiar it was (as opposed to the eerie blankness that had overtaken his brother when he'd woken before that).

And when Sirius had pointed out that the Noble and Most Ancient House of Black had  _ Orion Black's _ whole repertoire of defences on it, Regulus had cast upon him such a withering glare that Sirius had almost felt like he was fifteen again, about to be lectured by his baby brother on the entire history of their House - and proceeded to remind him that, " _ Those defences are for intruders, not for family, and even Mother's Blasting Curse on the tapestry won't erase the fact that you  _ are _ a Black." _

Sirius had not much liked the reminder but if it made this mission easier, then so be it. He could not escape his wretched family, so he might as well use whatever he got from them for  _ good _ rather than the self-serving haughtiness that ruled every decision that almost every single Black made. 

"Well. Here goes nothing," Sirius muttered to himself as he edged down the alleyway. He'd never thought he would willingly be sneaking back  _ into _ his old home. 

Merlin, James was going to hex his head off once he found out. 

**

_ This was a bad idea _ . 

It was all Regulus could think as he waited, in agonising silence, in his brother's apartment. The ticking of the clock was the only sound besides his too loud steps as he wore a hole in the floor, and it did nothing to ease his nerves. His eyes kept flicking to it, just barely seeing the time past the panicked haze that blurred his sight. 

He hadn't realised he'd been holding back so much stress while Sirius had been here but now that he was gone -  _ right into the dragon's lair _ , he'd snarked before leaving - Regulus had no distraction from his thoughts and his memories. Now they tumbled around in his head, he, Regulus Arcturus Black, Death Eater- defector- traitor- supposed to be  _ dead _ , oh a second scorchmark to match Sirius's- _ do not say that name in my house-traitor-shame and disgrace to the Black family name- _ what would his mother  _ think _ , she'd gone sparse when Sirius had run away, her fury and heartbreak a fire that had never quite gone out, and when Father-

He stumbled, grabbed onto the dining table before him, breaths feeling strangely tight in his chest like a Squeezing Hex had been cast on his lungs and his legs would not cooperate, had been turned to jelly, his grip on the table slipped as the fine tremors that had wracked his body increased into full body shakes and he was on his knees, he couldn't breathe-  _ traitor, dead, shame disgrace _ \- 

There was a sudden change in the air around him and a sharp voice pierced through the stifling haze enclosing him in his panic- "So what the hell is-"

And then a warm solid presence in front of him, hands on his shoulders, a panicked " _ Regulus _ ?"

But Regulus could only gasp some more, could not lift his head out of his trembling hands, could not look past the haze of murky waters below him and shivering from wet cold dead and slimy hands grasping at his legs, out  _ I want out- I'm sorry I'm- _

"-Reg, come on, hey it's me, it's Sirius, yeah?" The voice, sharp, insistent, was hacking away at the panic crawling up his tight throat. "It's Sirius, look, look at me, alright, I need you to suck in a deep breath and  _ look at me _ , Reggie!"

Suck in-

Regulus forced himself to focus on the words, on-

_ Sirius is back _ . 

He reached blindly, desperately, up with one hand until he felt the cool leather of his brother's jacket, grasped at it, twisted it in his fist until he could feel the up and down of Sirius's own breaths, forced himself to copy the motions,  _ in _ ,  _ out _ ,  _ in _ …

"Shit, there you are," Sirius breathed out, loosening his tight grip on Regulus's shoulders just a bit. Regulus didn't know when he'd closed his eyes, but he breathed out steadily and opened them to finally lift his head and see Sirius crouched down in front of him, a look of intense worry in his stormy eyes. Regulus swallowed. His hand dropped from his brother's jacket and thumped on the ( _ solid, tiles, dry _ ) floor between them. 

The brothers stared at each other uncertainly for a moment before Sirius heaved a deep sigh and reached behind him for a bag. He tipped it upside down and the sound of heavy books thudded against the floor. 

Regulus didn't look down. Now that his panic had resided, he felt unbelievably small in front of his brother, who now more than ever embodied the in-control confidence that Regulus felt like he'd been failing to impersonate his whole sorry eighteen years of life. He had failed as a Black, failed as an heir, failed as a bloody  _ Death Eater _ for Merlin's sake… and now he was failing as a brother, for bringing this Dark mess right into Sirius's already heavily targeted front door. 

He had failed to  _ go _ as intended and now he was going to get his brother killed. 

After all, no one betrayed 'the cause' and lived to tell their tale. But he was going to take his books, and that wretched locket, and he was going to destroy it and ensure the Dark Lord would not live to terrorise more young lives; and he  _ will not _ fail in this mission. Sirius did  _ not _ need to know any more. 

"Well, I wasn't expecting a victory dance," Sirius said sarcastically when the silence stretched on, as he poked at the disguised books, "but you're welcome."

Regulus licked his lips and glanced at them. They were all there. "I… appreciate it, Sirius." 

"Right." His brother stared at him. "So. What's a horcrux?"

"I-  _ What _ ?" 

Regulus's hand shot out to pull the books closer, picking them up one by one to examine his defences with a franticness that, absurdly, made Sirius laugh. He stilled, breathing deeply, and stared up at his nonchalant brother, who did not seem to realise the unbelievably dangerous question he'd just asked. 

"You… How did you…" 

Sirius rolled his eyes. "Come on. Did you forget we've had almost the exact same lessons? Curse breaking? Protective spells? Father's one and only useful  _ life lesson _ -"

"Don't- no _ , stop _ ," interrupted Regulus, through gritted teeth and an all new panic. "I  _ told _ you-"

"Yeah, yeah, Dark magic, don't open, I've had my fair share of run ins too, Reg, that stuff isn't reserved for wannabe Death Munchers."

Sirius's dismissiveness was  _ grating _ . Merlin, he'd  _ forgotten _ . 

"You don't understand!" he burst out. Sirius blinked at him. Regulus growled in frustration, gesturing around him and feeling as if the  _ thing _ in his robe pocket was trying to burn into his skin. "You shouldn't have opened them, I  _ know _ you don't leave things alone, you always have to know  _ everything _ but you can't know about this! You don't understand the- the severity-"

"The severity of the research project that just about  _ got you killed _ , you mean?" Sirius said scathingly; his coolness had faded into rigid anger through Regulus's outburst and now he coiled his hands in his lap into tight fists, eyes like thunder raking over Regulus's face and now-covered arms and neck. " _ I _ don't need to know? It's big enough to send you on a bloody suicide mission, and then come to  _ me _ instead of  _ home to Mother _ \- enough to make you want to leave the most noble ranks of the Death Eaters? But  _ I don't need to know _ ?" 

Fury laced every word and Regulus flinched back, swallowing hard. "I didn't say…" 

"Yeah, well, you didn't bloody have to," Sirius said darkly, still glowering. "It doesn't take a genius to figure out." He paused, pressed his mouth into a hard line, then added quietly, "Plus you were muttering through your panic attack just now."

Regulus felt sick.  _ Traitor shame dead dead dead _ … He looked away from his brother's piercing gaze, unable to keep up his own anger, though the fear was present as ever. He wondered vaguely if he'll be living the rest of his undoubtedly short life running on fear and panic and couldn't hold back a huff of dark laughter. This whole day had gone almost completely off track, he had no plan going forward, no way (yet) to destroy the horcrux, no ally, and yet… 

"Reg?" Sirius prodded, the fury gone from his voice. 

Regulus sighed, still not looking at him. "I just… need a new plan, that's all." He lifted the cover of the first book in his lap, glancing past the Quidditch-cover camouflage charm to skim his eyes over his hurried notes in the margins of the most vile book he'd ever had the misfortune of reading. 

"To…?" 

Merlin, he never knew when to quit. 

And Regulus was  _ tired _ . 

"To stop the Dark Lord," he muttered, with a wry quirk to his lips. 

The stunned silence from his brother was  _ almost _ worth it. 

**Notes for the Chapter:**

> Guess who desperately needs therapy? Ugh, the trauma. Touch aversion, PTSD, shock? Check, check, and check. And yet he's still trying to think on his feet, two steps ahead; this brave Slytherin boy.
> 
> Thank you sooo much everyone who left kudos, bookmarked, and commented on the first chapter! You've all reminded me how good it feels to be writing again and sharing my messy ideas with others. <3 
> 
> Hope you enjoyed this chapter just as much - if not more! Unfortunately the next chapter most likely won't be done until the new year because I have WAY too many family things and holiday things coming up this month, so until then! :)


	3. Three

**Summary for the Chapter:**

> "Whatever getting that horcrux cost you, you can't destroy it alone," he bit out, "so you better suck up that _bleeding Black pride_ that's killed almost every single person in this blasted family, and _let me help you_!" 

The first thing Sirius was woefully reminded about his paranoid brother was that pulling straight answers out of him was like pulling teeth out of a sleeping dragon. 

The second thing was that he was actually quite gifted at it.  Older brother prerogative, possibly.

"So let me get this straight." He paced around his small kitchen once more, taking a swig straight from the bottle of Firewhiskey he'd thankfully found still unopened (he was bordering on the slightly delirious side of awake-for-too-long). He stopped in front of his brother, seated at the bench opposite, and pointed at him. "Your bleeding fucking heart for  _ Kreacher _ led you to this mad idea that Voldemort has a bit of his  _ bloody soul _ hidden away. Or had?" He peered sharply at Regulus, who was starting to look a little ill. "Where is it now? You- buggering shite, it's in your pocket isn't it?" he burst out as he suddenly recalled Regulus's weird protectiveness over his inner pocket. 

Regulus shushed him desperately, looking around in fear even though he knew Sirius had fortified his flat to the nth degree. "You don't need to shout it," he said resentfully, placing a hand again in paranoia over his robe pocket. 

Sirius leaned on the counter with a deep groan, shutting his eyes as he dropped his forehead onto the cool glass bottle in his hand. "Merlin's balls. Why are you carrying the bastard's soul in your pocket?" he mumbled. The Firewhiskey must be wearing off, he thought numbly, because his whole body felt extremely cold. "Why are you like this?"

"Well the plan was to destroy it," Regulus said defensively, dropping his hands. 

Sirius looked up at him in silence, mouth pressed into a line. “And did you?”

Regulus scowled back. 

Sirius swore on a sigh and scrubbed a hand down his weary face. "Right. And I assume you're hoping your sorry tale is going to make me forget about your-  _ those _ bruises." It was not a question. Regulus broke eye contact and scowled harder, and Sirius muttered a few more choice words under his breath before chugging down another quarter of the bottle.  _ Merlin help me with this stubborn idiot _ . He slammed his bottle down onto the benchtop and said loudly, " _ What _ was trying to  _ kill you _ ?" 

He felt a flash of vicious triumph when that got a reaction; too caught in it, too bloody  _ tired _ , too stressed, to notice that Regulus's startled face morphed too quickly into anger, until he was caught at the receiving end of the Black fury he'd never, ever, associated with his soft little brother. 

"Won’t you leave it alone- I'm handling it! We have something infinitely more important, if you haven't realised, something that can _change the course of this war_! And you don't get to pretend to care about my wellbeing now after two years of NOTHING!" Sirius flinched. Regulus gripped the edge of the bench before him, chest heaving, eyes wide and extremely dark; a frantic _thing_ swimming in them that Sirius didn't know, and didn't like. 

He set his jaw. " _ You _ came to  _ me _ , Reg." 

"And maybe I shouldn't have!" Regulus shot back, rigid in his seat but quivering; with rage, or fear, Sirius didn't know. He forced back a wave of the kind of pain he thought he’d buried years ago and instead seized on the anger that had been simmering all night - anger at his brother for being too weak to fight against their parents’ fanatic ideology, and at Orion and Walburga themselves for letting their precious son march to his death.

"Whatever getting that horcrux cost you, you can't destroy it alone," he bit out, "so you better suck up that bleeding  _ Black pride _ that's killed almost every single person in this blasted family, and  _ let me help you _ !" 

Regulus shot to his feet, chair falling back with a clatter, a thundering scowl marring his face. "I am living on borrowed time as it is, Sirius. The  _ only  _ thing you can help me with now is finding a way to destroy this locket.” And then he turned on his heel and marched across the living room towards the closest bedroom - the empty one - and slammed the door behind him.

“Fuck’s sake.” Sirius expelled a deep breath and chugged back the last of his Firewhiskey. His brother had always been predisposed to the Black melodramatics. It was almost comforting to know that hadn’t changed, at least, but the topic was too troubling for anything to bring much comfort. He was going to find out  _ what  _ had happened to Regulus prior to him finding Sirius’s flat, and then he was going to blast it - or them - to smithereens.

But with the sudden silence following Regulus's fit, he was made aware of the increasing pressure in his head and the whoozy feeling that made his vision swim ever so slightly, and knew that if he didn't get to bed soon he'll be regretting it once the sun was up…. Which, a quick glance at the clock showed him, was barely half an hour away. He groaned again. Throwing his empty bottle in the bin, he pulled out his wand and circled the flat once more, tapping and tugging at his wards almost mindlessly. 

He came to a stop at the dining table where Regulus's books lay and gathered them back into the bag before Banishing them to the room Regulus had gone in - he had to smirk at the muffled sound of his brother's startled yelp followed by a grumbled " _ Sirius _ !" 

_ He _ could get his headstart on research. Sirius, meanwhile, was long overdue a date with his bed. 

**

It figured that he would not get an uninterrupted few hours of sleep, but instead be woken by James's voice calling out and startling him awake. 

"Padfoot? Padfoot! Oi, Sirius!"

Groaning, Sirius reached out a hand and fumbled through the mess on his bedside table to look for his two-way mirror, swearing at the headache already pulsing at his temples before his hand came into contact with the mirror and he could lift it up to squint into it.

“What?” 

James’ face moved further away - he’d clearly been shouting right into his own mirror - and he frowned at his best friend. “What do you mean,  _ what _ ? Did you  _ just _ wake up? You left our place at two! Were you drinking alone again? You look like utter shit.”

Sirius rubbed a hand down his face and propped himself up on an elbow, blowing out a breath. “Prongs, what-”

But Lily’s voice interrupted him, tight with anger or concern, and he caught a flash of her hair over James’s shoulder, “Your Floo is  _ blocked _ , Sirius!”

“Yeah, that’s why I called,” James added, the crease between his eyebrows deepening as he peered at Sirius, who swore under his breath. “Had us a bit worried, mate - are you even at home? Did you go home last night? ‘Cause clearly you’re  _ fine _ but if you didn’t go home and they’ve gotten to your flat- Wait, we need to tell Moony somehow-”

“Mate, relax,” Sirius cut in, swinging his feet to the ground and sitting up; he had to think fast. He thought he’d get at least a full day before anyone tried contacting him but clearly not. “I’m home, you idiot, I’m the one who blocked it-”

“Oh Merlin, really?” James made a show of rolling his eyes. “Where’d you pick up a girl at 2- you know what, nevermind…”

“Of  _ course _ he did,” Sirius heard Lily mutter in the background. He silently thanked his lucky stars that James couldn’t keep his gob shut for two seconds and had come up with his excuse for him. He let himself smirk slowly, relaxing again.

“Don’t get your knickers in a twist. Merlin, you couldn’t even go a night without me? Oi Lily, should I be concerned?" 

"Should  _ I _ ?" Lily demanded, pulling a face at him over James's shoulder, and James rolled his eyes. 

"Yeah, yeah, take the mick. Well, since you're clearly  _ not _ under threat of being murdered a brutal and lonely death, you're free to return to your beauty sleep now," he said with a haughty sniff. 

Sirius snorted. "Gee, thanks, Your Highness."

"You're ever welcome, Padfoot."

"Prats, the pair of you," Lily muttered; Sirius smirked at her before ending the mirror-call. As soon as it faded back to his own reflection, he let the smirk drop and leaned back with a gusty sigh. He could not imagine the shitstorm he'd currently be in if James had jumped out of his floo to find  _ Regulus _ in his face. 

It would've been a more violent awakening, that was for sure. 

Figuring he better check up on his angst-ridden little brother, Sirius pulled on his clothes and left his room, shutting the door behind him. The door adjacent to him was also shut, and the lights still off in the living room, though the blue glow from under Regulus's door hinted at him being up. Sirius stuck his hands in his pockets, rocked back on his heels for a moment, before calling out his brother's name. 

There was a second of silence. 

"What?" Regulus called back without opening. 

Sirius rolled his eyes. "Just checking you're still breathing fine," he said loudly, thumping the door with a fist. He had a funny vision of doing the same years back, mockingly asking for the ‘express permission of Regulus Arcturus Black to enter his humble abode’.

There was a  _ thump _ and an audible sigh from inside before the door clicked open. Smirking slightly, Sirius pushed it and stuck his head in. The floor of the room was - surprise, surprise - littered with open books and parchment that was, no doubt, organised in a meticulous manner.

He made a great show of stepping over them gingerly towards Regulus, lounging on the bed with a thick tome in hand. "Good to see  _ you've _ been resting," he said cheerfully.

Regulus rolled his eyes. "What do you want?" 

"Is that any way to speak to your elder brother?"

"My apologies. What do you want, you twat?" 

"My, my," Sirius said drolly, leaning in to squint at the gruesome picture he'd glimpsed on the page Regulus had open. "What would mother say… Is that Fiendfyre?" 

Regulus glanced down with a grimace. "For a horcrux to be destroyed, its vessel must be damaged beyond magical repair." He recited it without inflection, like he’d been repeating the same information to himself all night. Sirius did not doubt for a second that his swotty brother had been studying this topic harder than any OWL or NEWT - and that really was saying something.

The things they do for the war effort.

"Well, there goes my plan of slinging it out the window," Sirius muttered. He almost missed the dangerous flash in Regulus’s eyes but definitely didn’t miss the way his fingers twitched towards his pocket - that damned _locket_ \- before he clenched them in his lap, forcefully. It was like puzzle pieces clicking in his head and Sirius blamed last night’s, well, _lateness_ for how slow his brain was working because he _knew_ his brother, two years’ difference be damned, and for all that the Black blood had passed on some shitty ingrained traits and anger issues, that Dark _thing_ swimming behind Regulus’s eerily stiff stare since last night certainly had nothing to do with him unleashing a hidden well of the infamous Black temper - and absolutely something to do with _carrying_ _Voldemort’s soul in his pocket_.

Sirius didn’t realise he had his wand in his hand until he tried to  _ “Accio _ locket!” and all that happened was Regulus jumping back with his own wand raised in a heartbeat.

And no locket flying out of his pockets.

“What the  _ hell _ , Sirius?” Regulus shouted. His book fell to the floor with a  _ thump _ and his eyes looked mildly crazed.

Sirius had to, uncomfortably, concede to himself that  _ this _ time the latter was probably more due to the shock of thinking his supposedly safe older brother was trying to attack him, rather than a side effect of the horcrux. It would not do to admit that though. He shrugged instead. “Testing a theory?” He dropped his wand, refusing to feel sheepish. He did not  _ do _ sheepish. Prongs would laugh at him until his guts fell out, the knobhead. 

Regulus was still staring at him, wand hand lowering slightly. “And you could not have  _ asked _ ?” The amount of sarcasm dripping from his words could melt a glacier. 

“Would you mind, ever so kindly, taking the most evil object I’ve ever seen in my life out of your bloody pocket and depositing it somewhere  _ not _ on your, or my, immediate persons?” Sirius asked, then paused in brief thought. “I’ll admit that was a tad overkill-”

“You don’t say.”

“-I’m not sure No-Nose’s soul bits are objectively more evil than Great-Grandfather’s, well, everything,” he mused.

Regulus looked pained. “Please don’t… say soul bits ever again.”

“Yeah, you’re right. One soul bit’s more than enough,” Sirius agreed, then promptly scowled. He stuck out his hand, fixing Regulus with a glare. “Alright. Let’s see it, then.”

Regulus sighed but slipped a hand into his pocket, setting his jaw in a familiar determined look before pulling out a long golden chain, a heavy locket swinging from it. He didn’t seem to want to so much as look directly at it, and when he dropped it into Sirius’s waiting hand, Sirius could almost understand why. The thing  _ reeked _ of Dark magic. Growing up around in a landmine of Dark artefacts had honed their senses to what should be avoided, and  _ this _ was definitely stronger than most things in Grimmauld. Sirius swore quietly as he peered at it. The snake was so typical he could have laughed, if not for the vague sensation that it would probably come alive and rip his face off - or worse - if he so much as touched it directly. He gingerly grabbed it by the chain and lifted it up, looking at his brother.

“So. Where do we start?”

Regulus’s eyes shot up to his, questioning. Sirius cocked his head with a grim smirk. 

“You think I’d let you take  _ all  _ the glory of destroying the Dim Lord?”

Regulus glanced at the locket, a shadow passing over his face, before looking back at Sirius with a faint quirk to his lips that was much more familiar. “You wouldn’t be a Gryffindor if you did.”

“Oh, definitely.”

The locket almost hummed in the air between them; but it would stand no chance against the Black brothers. Sirius was sure of that.

**Notes for the Chapter:**

> The response to this fic has been overwhelming, guys! Thank you to every single person who comments and leaves kudos, they're like little happy bubbles every week :) 
> 
> Ah, these boys. A few things:  
> 1\. They really are awful at talking through their respective issues, in any way that is not shouting.   
> 2\. James was the mum!friend of the Marauders. You can't convince me otherwise.  
> 3\. Sleep-deprived and tired Sirius: shouty, loud, rash, angry. Rested Sirius: jokey, goes along with Reg's wishes, still rash but less shouty about it.  
> 4\. Sirius and James have definitely gotten high and come up with a series of unflattering alternative names for Voldy. Like, what a conceited git, calling himself Lord Voldemort and then expecting everyone to be too scared to say that? Ugh.


	4. Four

**Summary for the Chapter:**

> In which Regulus hits Sirius with a shocking tidbit of information; Dumbledore is involved (though not in the way you would have expected); and then Sirius gets his second shock of the day - though not entirely unwanted.

They hit their first major roadblock when Sirius threw a remark about recruiting James and Lily’s help and insight on their horcrux-destroying mission. Upon hearing their names, Regulus was on his feet and shaking his head furiously. “No. No, absolutely not.”

Sirius stared at him. “What’s gotten up your-”

“Have you registered  _ nothing _ of what I’ve been telling you? Of how dangerous this thing is, of how dangerous  _ my being here _ is? And you want to throw your favourite Gryffindors into the mix?  _ Are you out of your mind _ ?”

“Oi, I trust Prongs with my life!” Sirius retorted, feeling a flash of indignation. “And they’re some of the brightest brains we’ve got, this kind of Dark magic is  _ heaps _ beyond what you and I grew up with, Reg, you  _ know _ we need-”

“We need nothing, and no-one! You don’t-” Regulus clenched his fists and took two steps towards Sirius, something like panic swimming behind his eyes; Sirius almost relented. “Your Phoenix lot may think you know what the Dark Lord is capable of, or what he plans to do, but he is  _ ahead _ of you, and this is our only chance. He’s- I’ve heard- oh.” And he stopped, remembering something, eyes widening as he stared at a perplexed Sirius. 

“He has a trusted spy in the Order.”

Sirius stared back at him, mouth opening but nothing coming out. The words spun in his head, the implications horrifying, shocking. “Who-” he managed, but Regulus was already shaking his head.

“I don’t know; he doesn’t share his secrets. But he has bragged enough about having an insight into Dumbledore’s plans, and his counter attacks have been much too precise in location and timing to be anything less than leaked information." He took a deep breath, flicking his eyes away from Sirius's pale face, a grimace marring his features. "It's… how we… how the Death Eaters ambushed…"

Sirius licked his lips, voice hollow when he completed, "Benjy's team, two months ago." Numb with shock, he swore, remembering the devastation of that particular blow to the Order; a reconnaissance mission that was meant to stop an attack on a Muggle village, but that had ended up in a trap and a complete obliteration of five skilled witches and wizards. They had recovered their bodies only to realise that Benjy Fenwick’s had been missing.

Moody had tracked down his… remains… only a couple weeks ago. 

“Who?” Sirius asked, his voice low; an undercurrent of fury slipping past the numbness. He could feel it burning in his veins, this rage as he realised the implicit trust each and every member of the Order supposedly had in each other, the secrets and plans only they knew amongst themselves, that they had  _ sworn _ to. Fealty to fighting the Dark, a battle none of them took on lightly when each person was approached by Dumbledore - the willingness to  _ die _ for each other, if need be. For the marginalised and for the oppressed amongst the wizarding community, for the Muggles who lived in naive peace. 

Who would  _ betray  _ that?

“I wish I could tell you.” Regulus’s voice was distant through the roaring in Sirius’s ears. “But the Dark Lord holds his secrets closely-”

“And will you  _ quit calling him that _ ?” Sirius snarled automatically, making Regulus’s mouth snap shut. He pressed his lips in a thin line, a familiar glare hitting Sirius, who felt a flash of remorse for snapping at his brother but not enough to take it back. It didn’t help matters  _ at all _ to constantly hear the moniker for Voldemort that only Death Eaters used coming out of his brother’s mouth.

Regulus rolled his eyes, snark dripping from his voice. “ _ You-Know-Who _ doesn’t share his secrets - not outright, anyway,” he added darkly.

“What’s that supposed to mean?” Sirius pressed, frustrated by the obscure non-answers Regulus kept spouting.

He sighed. “It  _ means _ he will hint at his proudest plans to constantly instill fear and awe into his followers, but he doesn’t expect anyone to be putting together the pieces. An oversight, I think, considering most of the Death Eaters are Slytherin…”

Sirius stared hard at him, thinking past his anger. “A megalomaniac; not surprising. Right. This is- I need to let Dumbledore  _ know _ .”

Regulus looked up, meeting his eyes in panic. “You said you won’t-”

Frustrated, Sirius shook his head. “I won’t mention you, but he  _ needs _ to know there’s a spy- I’m not risking anyone else walking into a trap!”

“He’ll want to know how you know,” his brother pointed out, still on edge. Funnily enough, his visible stress made Sirius relax a little, a smirk lifting his lips.

“Why, Reggie, it’s almost like you’ve forgotten where my talents lie. I’ll sort it out; and if you can pick your brains for any hint of  _ who  _ this rat could be, it’ll be easier.” He lifted a hand to clap Regulus’s shoulder -

And Regulus  _ flinched _ , eyes squeezing shut for a second before he turned his head sharply to stare at the wall; his jaw clenched so tight it had to hurt. There was a tense pause, before he let out a sharp breath and said, “I will try.”

Sirius dropped his hand, flexing his fingers in frustration. He had to firmly remind himself of Regulus’s visceral reaction yesterday when he pushed for answers, the complete shut down he’d received; he wasn’t entirely certain all of that was a reaction to the horcrux’s proximity at the time, because the Darkness he’d glimpsed swirling behind his brother’s eyes hinted at something  _ else _ . And the bruises… the  _ suicide  _ mission… 

“Alright,” he eventually said, feeling the familiar urge to move and  _ do _ something useful. “Let’s get to it then.”

***

James tossed an old quaffle from his spot on the couch, catching it when it bounced back off the wall with a dull  _ thunk _ . He huffed and pressed his head into the thick leather. 

"What's Padfoot even  _ up to _ ?" he complained.

Lily lowered her novel and peered at him, her brilliant green eyes narrowed. "James. Love. It’s only been - hmm - a few hours since we spoke to him. He might be sleeping. Silence in the mirror doesn't have to mean  _ trouble _ ."

James groaned. "I  _ know _ , I'm not just being a worrywart. Lils, I can  _ feel _ it. The knobhead's got some stupid plan in his head. He blocked his Floo! When has he  _ ever _ blocked his Floo?" 

"Well… fair point," she conceded with a grimace, propping her book face down in her lap. She shook out her hair (James looked up for a moment to admire the way it curled around her face - his wife was  _ gorgeous _ ) and then nodded; a gleam of determination in her eyes that meant she'd made up her mind. James sat up in response. "Shall we go, then?"

James beamed at her. She  _ did _ always get it. 

***

The lonely streets of Hogsmeade stretched before him. It was eerie, he couldn’t deny. He’d never seen the village so  _ quiet _ . 

The trudge up to the castle was a long one; he had the funny thought that he’d never before walked it alone, the other three Marauders a constant presence throughout his schooling years (or sometimes two, or one, when detentions ate away at their Hogsmeade weekends). Granted, he’d hardly been called to the Headmaster’s office while a student, besides those two singularly  _ highly _ unpleasant days, and had definitely seen more of the room as an Order member, so he couldn’t help but feel a bit antsy at the fact that none of his friends knew he was here - or  _ why _ . 

He sighed. Maybe he’d convince Regulus at another time. For now, he had to stay focused on not letting on to Dumbledore more than he had promised to share. Much as he trusted his old Headmaster and Order leader, he knew that piercing and too-knowing gaze had some way of finding out  _ more _ than the person on its receiving end vocalised. The man wasn’t known as Britain’s most powerful wizard for nothing, after all. 

Luckily for Sirius, he had a good few years of diverting attention away from the prying minds of his family under his belt. And so it was knowledge of the spy, and nothing else, that he thought of on his way up to the castle.

**

The thick doors shut gently behind him as he stepped into the grand Headmaster's office. Dumbledore was seated behind his desk, fingers laced before him as he peered into one of his many odd instruments. He looked up as Sirius entered, a smile gracing his features as he beckoned him forward.

“Ah, Sirius, welcome.”

“Afternoon, sir.”

“Yes, good afternoon. I trust your last mission went well? Although I am sure you will regale us of a most dramatic retelling at the next meeting,” he chuckled, eyes twinkling.

Sirius allowed himself a smirk as he slid into the comfortable seat opposite the Headmaster. “It did. And you know we have to spice those meetings up somehow, sir; we’re not the Order of the  _ Phoenix _ for nothing.”

“Oh, I do agree." Dumbledore hummed and nudged forward a bowl of sweets; he eyed his former student curiously as he continued, "But now, Sirius, you did not make this trip for small talk. Your message did seem quite urgent, if I was not mistaken.”

“Yes… you’re right.” Sirius took a lolly and stared at it, rolling it around in his hands for something to do while we sorted his thoughts carefully. His original fury at his brother’s words returned, a steady fire forcing him to take a deep breath before speaking, though there remained an undercurrent of heat simmering beneath his words. “I’ve become - privy - to a bit of information that threatens everyone in the Order. I’m - there’s… there seems to be a spy, sir, in our ranks,” he growled.

There was a brief silence before Dumbledore spoke, his earlier lightheartedness replaced with a tone of steel. “That is most concerning… And quite a statement to make, with such confidence. I must ask, Sirius, from where - or from whom - you obtained this information.” 

Sirius lifted his gaze but let it wander over the portraits of Headmasters and Headmistresses behind Dumbledore; most faking sleep, except for - he noted with an uncomfortable jolt, the sneering face of his own Black ancestor glaring down at him. He spoke slowly, letting uncertainty colour his words. “It’s not my place to say - just yet. For safety’s sake, you know. I promise it’s a trusted source, though. And - you have to admit, sir, it makes a lot of sense; they’ve - the Death Eaters - been one-upping us for a while now, and it can’t all be a coincidence. They must have someone leaking them information. We all know Benjy and his team walked into a trap two months ago,” he added, speaking quickly now, anger making his voice tremble slightly. He had a sudden thought, an awful one that almost made him feel sicker than the idea of a deliberate spy in their ranks; “and maybe it’s not a willing spy, sir, maybe they’ve tortured the information out of someone, or- or  _ Imperiused _ them, I don’t know. But it’s worth looking into. If we can’t trust everyone in the Order, then what do we  _ have _ ?” he said fiercely, finally looking at Dumbledore, but unable to shake from his mind the terrible images of one of his friends being possibly tortured without the rest of them even  _ knowing _ . 

Dumbledore gazed back at him with his piercing stare for a few moments, before sighing and turning his eyes to the empty cage by the window that usually held Fawkes. “That is, of course, all plausible. I’m afraid we must expect and entertain all possibilities from Voldemort, and I fear I may have failed and grown lax in my judgements if he has been able to withdraw such vital information of our plans from one of our own trusted members.” He fell silent then, clearly deep in thought. Sirius waited for more questions, but it seemed he was to be let off the hook easily today, for his Headmaster simply added after a couple of silent minutes, “I thank you, Sirius, for bringing this most troubling news to my attention discreetly. You can rest assured I will handle our Order’s situation accordingly.”

Taking his cue to leave, Sirius nodded, tapping the table in front of him lightly as he stood. “Of course, sir. I’ll see you at the next meeting, then.”

**

Deep in thought of who had infiltrated the Order’s ranks and how and most baffling of all,  _ why _ , Sirius wasn’t sure what he was expecting when he got back to his flat - naively, possibly just his brother neck-deep in research and spellwork. But it  _ definitely _ was not the sight of his brother-by-blood and Marauder-brother sitting across from each other in chilly silence, with an equally tense Lily Potter standing behind her husband, arms folded and wand in hand. 

The door clicked shut behind him, and three accusatory glares hit him simultaneously. 

“Er. Lily. Prongs. Mate.”

“Hello, Sirius.”

“Padfoot.” 

Sirius edged into the room, tossing his leather jacket over the nearest chair without taking his eyes off of James’s face. James narrowed his eyes at him in a silent demand, and Sirius shrugged in response, flicking a glance at a carefully stoic Regulus who sat tight-lipped and upright, hands clasped in his lap. Sirius recognised the non-threatening gesture for what it was, but knew that the carefully tightened lid Regulus kept on his emotions would be at spilling point from being sprung on by the two Order members (or Gryffindors, whichever offended him most at the moment) he had expressed his wish to specifically be kept hidden  _ from _ .

“So… I notice you’re all still in one piece.”

“Not for lack of trying,” James muttered, with a distrustful look at Regulus. Lily fingered her wand, eyes flashing dangerously, but rested her free hand on James’s shoulder.

Letting out a deep sigh that was half-groan (could this week get any more stressful?), Sirius crossed the room and threw himself onto the other end of the couch Regulus was seated at, still doing his best imitation of a statue. He raked a hand through his hair, thinking quickly. “Look, I’ll explain what I can-”

“What you  _ can _ ?”

“Prongs, trust me when I say you don’t want the whole story right now."

“Fine, you twat, but begin with when and how your  _ Death Eater brother _ became your new flatmate?” demanded James, waving his hand wildly at Reg.

Sirius snorted. “Okay, firstly, he’s - er - decidedly not a Death Eater… anymore.”

James threw both hands up at this explanation. “Of course! And Voldy just  _ handed  _ him his resignation?” 

“Don’t be a knobhead, mate. Of course not,” Sirius said idly, glancing at Regulus, who was frowning at him in warning. He rolled his eyes. Great - now he had two of the most dramatic people in his life not trusting him. “As for  _ when _ , well, only yesterday.”

“ _ That’s _ why your Floo was blocked! See, Lils, I  _ told _ you that wasn’t normal,” said James accusingly, before diverting his attention back to Sirius. “You liar, there never was a  _ girl _ .”

“Well, James, that was  _ your _ assumption, to be fair,” Lily cut in, and Sirius was relieved to see she had relaxed a fraction - presumably at Sirius’s own lack of alarm. James may be dramatic in his hurt of being kept in the dark, but that was nothing compared to Lily’s anger if she felt Sirius was legitimately being threatened.

Not that she would voice such a concern, but they were (funnily enough) similar in that way, that Sirius could predict her reactions easily. 

He slid his eyes over to Regulus again, who was not looking too pleased or amused in the slightest. Cocking an eyebrow back at James, he asked, "Since when do you two make house visits anyway?"

"Since I knew you were  _ hiding _ something," said James with another scowl at the younger Black. 

Of course, Regulus had to scoff at that.

James narrowed his eyes at him. "What?"

"Nothing," Regulus said, coolly. 

"And he speaks! Tell me, baby Black, what makes a Death Eater not a Death Eater?" 

"Nothing that's any of  _ your  _ business, Potter."

Sirius met Lily's eyes with a despairing look. He knew this was going to happen; the two had never so much as exchanged nods, let alone had a single pleasant exchange. He knew James was just overly protective, and Regulus distrusting, but this wasn't merely a brief encounter so he definitely had to step in this time.

"I can't believe I'm playing Moony's advocate here," he muttered, then said loudly, "Alright, knock it off, you two. Prongs, trust me when I say he's on our side; and Reggie, lay off the hostilities."

Lily broke the silence that followed with a snicker. They all turned to look at her, and she shrugged, tucking her wand neatly back into her pocket. "Sirius Black breaking up a fight before it's started. Wonders never cease."

"Ah, shut up, Evans."

"That's Potter, Black," she winked, and Sirius grinned back at her.

James broke the moment by sitting back with a displeased huff. "Fine.  _ But _ ," he added fiercely, looking first at Regulus then at Sirius, who cocked an eyebrow at him, "whatever you're planning, we want in, dangerous or not."

Sirius held up his hands. "Not my call, mate, sorry." James looked bewildered for a moment before cocking his head at a pensive Regulus.

"You may… be of some assistance," he conceded slowly, glancing between them before resting his gaze on Sirius. "We will discuss it."

Sirius held his gaze before letting out a breath, feeling his shoulders lighten a bit. He nodded and shot James and Lily a wry look.

"Like I said. His call."

James responded with a begrudging hum. Lily patted his arm, sending Regulus a warm nod over James's head. Regulus inclined his head in return, and Sirius could only huff at them all. 

"I can't _ believe _ you've all made me play at being the diplomat," he muttered, and James finally cracked a grin. 

"And to think, it  _ almost _ suited you."

"Piss off."

**Notes for the Chapter:**

> Me, writing these scenes, pained but unable to stop: quit using 'eyes' and 'gaze' and 'looked' pls  
> Me at me: tHe EyEs ArE tHe WiNdOwS tO oUr SoUls   
> Also me: but also ??? other body language ????? EXISTS ???????  
> Also, also me: i am writing for fun and we are not nit-picking, end of story
> 
> (Also, james is SUCH a mum friend. he is 100% the mum-friend of the Marauders. have i said this before? idc i'll say it again.) (btw fyi i love my Dramatic Sons)
> 
> hope you enjoyed as much as i enjoyed writing all those arguments, even if i do have a teeeeensy bit of an issue with constantly jumping between serious vs. sarcastic/mocking conversation but i blame it on the kiddos. and another thing, dumbledore is weird to write but i promise i have his inner workings all... worked out. this won't be the end of his and sirius's convo, that's for sure.


End file.
